1. Department of Gastroenterology Shanghai Tenth People’s Hospital School of medicine, Tongji University 200072 Shanghai China
2. Department of Gastroenterology Shidong Hospital, Yangpu District Shidong Hospital Affiliated to University of Shanghai for Science and Technology 200433 Shanghai P.R.China
3. Department of Gastroenterology Putuo People's Hospital Tongji University 200060 Shanghai China